Rear End Ratio - Speed - RPM - Tire Size Calculator
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Fill in 3 of the 4 values then click the corresponding "Compute" button. Metric values are not supported and don't use letters...use numbers only.  You can find out some useful information (how will changing tire size affect your speedometer reading?)


Enter: Engine RPM, Tire Diameter and Speed


Enter: Engine RPM, Tire Diameter and Gear Ratio


Enter: Tire Diameter, Speed and Gear Ratio


Enter: RPM, Speed and Gear Ratio
Enter the Engine RPM
Enter the Tire Diameter (inches)
Enter the Speed (Miles per Hour)
Enter the Gear Ratio - 3.0 for 3.0:1